Refrigeration evaporator fan motor controller for freezers

ABSTRACT

A system for use with freezer/refrigeration devices comprising: a fan speed controller, at least one remote air sensors, and a voltage control device.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of PPA Ser. 60/605,408 filed on Aug.27, 2004 by the present inventors.

FIELD OF THE INVENTION

The present invention relates to an apparatus and accompanying methodsfor the energy savings of various products.

BACKGROUND OF THE INVENTION

Currently, the marketplace does not offer an evaporator fan controllerspecifically designed for freezers but can be used with mediumtemperature systems utilizing a temperature sensor to regulate fanspeed. Freezer and/or other medium temperature refrigeration systemswhich are in operation today are not quite as efficient as they can be.One of the problems which inhere with most refrigeration systems is thefact that the refrigeration fans are operating at high speeds most ofthe time irregardless of whether the temperature inside requires thefans to be at high speeds. In addition, maintaining fans at a highspeeds requires the expenditure of great amounts of energy which is verycostly.

It will be pointed out here that no temperature differential indicatesthat the compressor is not running. Whereas the existence of atemperature differential indicates that the compressor is on, whichmeans that it will be necessary to keep the fans at high speed.

Another problem with the current systems is that under normal systemoperation with no fan controller when the box reaches pre-settemperature input the fans remain running when the compressor is off andthese fans generate approximately 200 Watts of heat per fan when usingshaded pole motors. And the heat generated by these fans increases theheat load in the box which brings the compressor back on.

When designing a box the heat of the fans must be taken intoconsideration when sizing the system. Compressor must take away theadditional heat produced when fans are unnecessarily running. The energycost is paid twice because of the unnecessary running of fans whencompressor is off. The compressor must take back the heat generated whenit was off. This thereby shortens the off-cycle of the compressor.

There are patents which have attempted to reduce the energy expenditureof refrigeration systems. U.S. Pat. Nos. 5,488,835 and 5,797,276 pertainto the present invention. The drawback to these inventions is the factthat the technology used is somewhat outdated and more cumbersome thanthe present invention. U.S. Pat. No. 6,397,612 uses a current sensor inorder to determine whether the refrigeration system fans should beshifted to lower speeds. The drawback to this invention is the fact thatthe current sensor is dependent on a solenoid valve as well as athermostat which many systems do not use one.

Another problem with the other inventions is that most systems aredependent on the temperature of the actual coil and warm copper piperunning to it to sense the temperature.

Another problem with other inventions such as U.S. Pat. No. 5,488,835 isthat it's use is predicated upon a thermostat and the temperature acrossthe the expansion valve. This system is not adaptable for a freezerbecause this system is operated mainly above 28° F. whereas mostfreezers are operational between the temperature range of −10° F. and−20° F. The present invention is an improvement upon this patent becauseit does not require the use of a thermostat nor does it require anexpansion valve. Accordingly, there is no prior art which isspecifically adapted for and designed for use with freezers. The priorart deals exclusively with refrigeration systems of medium-rangetemperatures.

It is to be understood that the term “prior art” as used herein or inany statement made by or on behalf of applicants means only that anydocument or thing referred to as prior art bears, directly orinferentially, a date which is earlier than the effective filing datehereof. No representation or admission is made that any of theabove-listed documents is part of the prior art, or that an exhaustivesearch has been made, or that no more pertinent information exists.

SUMMARY OF THE INVENTION

The compressor is the main energy user in all freezer and/orrefrigeration systems. The main focus of the present invention is tokeep the compressor off for as long as possible for maximum energysavings and this can be achieved by reducing the heat load in therefrigerated chamber. By reducing the fan speed when the compressor isoff is where we achieve our approximate 85% energy savings and heat loadfrom the fans by not adding the heat of the fans to the box. Thetemperature control device stays off longer whether a thermostat orother switch. This can be achieved by reducing the heat load in therefrigerated chamber.

Another main objective is to provide a system wherein no thermostat orsolenoid valve exists within the chamber but the temperature iscontrolled by a pressure device outside the condensing unit. Likewise,it is known in the art that some systems modulate the temperaturethrough a remote monitoring system by a computer. When the compressorstarts there is a temperature differential across the coil usually10-15° F. which is sensed by the remote air sensor.

Another critical objective of the present invention is to provide ameans of detecting the temperature of the air entering and leaving thecoil. This is a significant improvement upon the prior art because thismakes the system operational with freezers. In addition, thisimprovement enables the system of the present invention to beoperational with freezers, whereas the prior art such as U.S. Pat. No.5,797,276 will not work at temperatures under 28° F.

And yet another object of the present invention is to ensure that thesystem is not predicated upon the use of a thermostat or a specificmetering device. The problem with other inventions such as U.S. Pat. No.5,488,835 and U.S. Pat. No. 5,797,276 is that it's use is predicatedupon a thermostat and the temperature differential across the expansionvalve. The present invention is an improvement upon this patent becauseit does not require the use of a thermostat nor does it require thetemperature differential across the expansion valve. The presentinvention does not require the use of a thermostat because thetemperature is measured off the air which emanates in and out of thecoil. And whereas said patent relies upon a temperature differentialacross the expansion valve, the present invention measures thetemperature differential between entering and leaving airstreams off thecoil under normal operation. This feature may also be adaptable formedium-range temperature units as well.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

FIG. 1 a illustrates a preferred embodiment of the present invention.

FIG. 1 b illustrates a preferred embodiment of the present invention.

FIG. 2 illustrates a preferred embodiment of the present invention.

FIG. 3 illustrates a flow diagram for use with the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

A unique system, apparatus, and accompanying methods are used toregulate fan speeds with freezers and other refrigeration systems. Thepresent invention is described in enabling detail below.

FIG. 1 a and FIG. 1 b illustrate one preferred embodiment of the presentinvention. Arrows indicate entering air stream and a discharged airstream in FIGS. 1 a and 1 b. Fan control system 100 comprises a voltagecontroller 101, a temperature sensing relay 102, remote air sensor(s)103, and an evaporator fan motor(s) 110. Remote air sensor(s) 103 areplaced in the entering air stream of the evaporator coil 104 and at thepoint where the discharged air comes off the evaporator coil 104. R1 111will hereafter denote remote air sensor 1 and R2 120 will hereafterdenote remote air sensor 2.

It must be pointed out here that the present invention does notnecessarily require the use of a solenoid for any portion of theoperation. The present invention may be used with a standard thermostatbut does not require one. This is an advantage and a significantimprovement over the prior art. In addition, although the presentinvention is specifically adapted for use with freezers, the presentinvention may be suitable for other medium and high-temperature adaptedrefrigeration systems.

Most of the components used in the present invention are readilyavailable and understandable to one skilled in the art. Voltagecontroller 101 is well known in the art and it is of no consequencewhich type of voltage controller controller 101 is used inasmuch as itbe adaptable with the rest of the components of the present invention.

The type of evaporator fan motor 110 is also well known in the art andthe type is not specifically required as long as it is a shaded pole orPSC (permanent split capacitor) type motor. The present invention is notlimited in applicability to refrigerated chambers, the refrigerationsystems of which comprise evaporator fan motors of a particular type,such as series wound motors. The motor is generally recognized withinthe refrigerated industry and it is typically a shaded pole or PSC typemotor. The only requirement is that the evaporator fan motor 110 whichis used is readily adaptable for used with the rest of the components inthe present invention. The present invention is also not limited inapplication to refrigerated chambers the refrigeration systems of whichemploy two-speed motors as evaporator fan motors.

The present invention is not dependent upon which kind of meteringdevice is used to modulate refrigerants into the evaporator. Remote airsensor (s) 103 are also well known in the art and is readily availableto one skilled in the art. It is of no consequence which remote airsensor 103 is used inasmuch as it work properly with the rest of thecomponents of the present invention. The temperature sensing relay 102is also well known in the art and is readily understood by one skilledin the art. It is of no consequence which temperature sensing relay 102is actually used in the present invention inasmuch as it work properlywith the rest of the components of the present invention.

The voltage controller 101 may embody many different types such as thetriac, the quadrac, or other similar devices. It is not specificallyrequired in the present invention that any particular device be used.There abound several types of voltage controllers which are well knownin the art which may prove to be equally useful in the presentinvention. The mentioning of the triac or the quadrac is for exemplaryor illustrative purposes only. The triac is well-known in the art andreadily available to one skilled in the art. The particular triac whichis used is of no consequence inasmuch as it works properly with theother components of the present invention. In the art there are two wellknown triacs: one is 230 Volt and the other is a 120 Volt triac. It isof no consequence which triac is used between these two or any othertriac-type device. In addition, some triacs are made with differentamperages. Inasmuch as triacs and other similar voltage controllers varywidely with respect to amperages and voltages, the specific type used isof no consequence insofar as it is compatible with the rest of thecomponents of the present invention.

Moreover in the art there are quadracs. Quadracs may be used in place ofthe triac. Both the quadracs and the triacs are interchangeable for thepurposes and objectives of the present invention or any component oflike-description.

The voltage controller 101 is in communication with other components ofthe present invention through wires which will be described below. Twowires 111 and 120 are used for the remote air sensor(s) 103. (When thereis only one remote air sensor 103 or more than one remote air sensor 103more or less will be needed and reference characters should not beconstrued to be limiting the scope of the present invention). Wires 111and 120 are usually low voltage wires.

Wire 112 is a common power wire. Contact 113 is a normally closedcontact which transfers power to the voltage controller or directly tofan motor(s). Wire 114 is a normally open wire which closes when atemperature differential is detected across the coil. Wire 114 bypassesthe voltage controller 101. And wire 115 connects the voltage controller101 with temperature sensing relay 102. Wire 116 connects voltagecontroller 101 with the fan 110 on low speed operation where there is notemperature differential detected across the evaporator coil sendingpower through wire 114 and directly to the fan 110. Temperature sensingrelay 102 detects the temperature differential and switches the contactsin the relay from normally closed contact low speed to normally opencontact high speed sending power through wire 114 which is high speednormal operation.

FIG. 3 illustrates a preferred method of the present invention. First,in step one 201, remote air sensors 103 detect whether there is adifferential in temperatures between them. If there is a temperaturedifferential detected by the remote air sensor(s) 103 which indicatesthe compressor is running then fan control system 100 in Step two 202will maintain high speed of the evaporator fan motor 110. However, ifthere is no temperature differential which indicates that the compressoris not running, in step three 203, then evaporator fan motor 102 is setto a lower speed. By setting the evaporator fan motor 110 to a lowerspeed two important objectives are achieved. First, lower fan speedswill save upwards of 85% of energy of the fans along with a substantialamount of financial savings not to mention the fact that there is lessheat generated by the fans at lower speeds. And second, a lower fanspeed will ensure that there will not be a stratification of the airtemperature. As long as there is air circulation, the box will be at aconstant temperature. And third, by having a lower fan speed, the lifeof the equipment is thereby extended due to lower running times.

It will be apparent to the skilled artisan that there are numerouschanges that may be made in embodiments described herein withoutdeparting from the spirit and scope of the invention. As such, theinvention taught herein by specific examples is limited only by thescope of the claims that follow.

1. A system for use with freezers and/or other refrigeration typesystems comprising: a voltage controller, at least one remote airsensor(s), and a temperature sensing relay.
 2. The system of claim 1wherein the remote air sensor is in communication with the temperaturesensing relay.
 3. The system of claim 2 wherein the temperature sensingrelay is in communication with the voltage controller.
 4. The system ofclaim 3 wherein the voltage controller is a triac or similar type ofdevice.
 5. The system of claim 4 wherein the triac type device isintegrated with the temperature sensing relay.
 6. The system of claim 3wherein the voltage controller is a quadrac or similar type device. 7.The system of claim 6 wherein the quadrac type device or other similardevices is integrated with the temperature sensing relay.
 8. The systemof claim one wherein the voltage controller and the temperature sensingrelay is in communication with a fan motor.
 9. The system of claim onewherein at least one remote air sensor is placed in the discharged airstream.
 10. For use with a freezer system having a cooled chamber, acompressor, an evaporator fan motor, at least one remote air sensorplaced in the discharged air stream, a temperature sensing relay, and avoltage controller comprising: an evaporator fan motor in communicationwith a voltage controller, said voltage controller in communication withthe remote air sensor(s), the remote air sensor(s) sensing airtemperature from a front and a back of an evaporator coil, whereby ifthe remote air sensor(s) through the temperature sensing relay detects atemperature differential the evaporator fan motor will maintain a highspeed indicating that the system is cooling, whereas if the remote airsensor(s) does not detect a temperature differential the evaporator fanmotor will shift into a lower speed indicating that the compressor isnot running thereby decreasing evaporator fan produced heat, resultingin an overall decreased energy requirement for the heat exchange systemby keeping the fan heat out of the refrigerated chamber and by keepingthe compressor off resulting in substantial energy savings.
 11. A methodfor use with the system of claim 1 comprising: (a) detecting whetherthere is a temperature differential on an evaporator coil using at leastone remote air sensor or plurality of remote air sensors; (b) settingthe speed of evaporator fan motor(s) to high speed when there is atemperature differential across the evaporator coil, whereby it isindicated that the compressor is running; (c) setting the speed ofevaporator fan motor(s) to low speed when there is no temperaturedifferential across the evaporator coil, whereby it is indicated thatthe compressor is not running.